crypto: estimate kExternalSize

Based on a build of OpenSSL 1.1.0f.

The exact sizes are not particularly important (the original value was
missing all the objects hanging off anyway), only that V8 garbage
collector be aware that there is some memory usage beyond the sockets
themselves.

PR-URL: #16130
Reviewed-By: Ben Noordhuis <[email protected]>
Reviewed-By: Rod Vagg <[email protected]>

src/node_crypto.h

@@ -106,7 +106,13 @@ class SecureContext : public BaseObject {
   static const int kTicketKeyIVIndex = 4;
 
  protected:
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
   static const int64_t kExternalSize = sizeof(SSL_CTX);
+#else
+  // OpenSSL 1.1.0 has opaque structures. This is an estimate based on the size
+  // as of OpenSSL 1.1.0f.
+  static const int64_t kExternalSize = 872;
+#endif
 
   static void New(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Init(const v8::FunctionCallbackInfo<v8::Value>& args);
@@ -220,11 +226,17 @@ class SSLWrap {
  protected:
   typedef void (*CertCb)(void* arg);
 
+#if OPENSSL_VERSION_NUMBER < 0x10100000L
   // Size allocated by OpenSSL: one for SSL structure, one for SSL3_STATE and
   // some for buffers.
   // NOTE: Actually it is much more than this
   static const int64_t kExternalSize =
       sizeof(SSL) + sizeof(SSL3_STATE) + 42 * 1024;
+#else
+  // OpenSSL 1.1.0 has opaque structures. This is an estimate based on the size
+  // as of OpenSSL 1.1.0f.
+  static const int64_t kExternalSize = 4448 + 1024 + 42 * 1024;
+#endif
 
   static void InitNPN(SecureContext* sc);
   static void AddMethods(Environment* env, v8::Local<v8::FunctionTemplate> t);